Multiple-element light-bending structures for minimizing display borders

ABSTRACT

An electronic device may be provided with a display mounted in a housing. The display may have an array of display pixels that provide image light to a user. The array of display pixels may form an active display structure with a rectangular shape. The rectangular active display structure may be surrounded by an inactive border region. Optical structures such as upper structures formed from a sheet of glass and lower optical structures that lie beneath the sheet of glass may be configured to bend light from the display pixels along the periphery of the active display structure. The upper optical structures may have an area that is larger than the area of the active display structure, so that the presence of the optical structures may serve to enlarge the apparent size of the display. The lower and upper optical structures may have curved surfaces for bending the light.

This application is a continuation of patent application Ser. No.16/774,180, filed Jan. 28, 2020, which is a continuation of patentapplication Ser. No. 16/006,714, filed Jun. 12, 2018, now U.S. Pat. No.10,551,874, which is a continuation of patent application Ser. No.13/631,141, filed Sep. 28, 2012, now U.S. Pat. No. 10,067,535. Thisapplication claims the benefit of and claims priority to patentapplication Ser. No. 16/774,180, filed Jan. 28, 2020, Patent applicationSer. No. 16/006,714, filed Jun. 12, 2018, now U.S. Pat. No. 10,551,874,and patent application Ser. No. 13/631,141, filed Sep. 28, 2012, nowU.S. Pat. No. 10,067,535.

BACKGROUND

This relates generally to electronic devices, and more particularly, toelectronic devices with displays.

Electronic devices often include displays. For example, cellulartelephones and portable computers often include displays for presentinginformation to a user. An electronic device may have a housing such as ahousing formed from plastic or metal. Components for the electronicdevice such as display components may be mounted in the housing.

It can be challenging to incorporate a display into the housing of anelectronic device. Size and weight are often important considerations indesigning electronic devices. If care is not taken, displays may bebulky or may be surrounded by overly large borders. The housing of anelectronic device can be adjusted to accommodate a bulky display withlarge borders, but this can lead to undesirable enlargement of the sizeand weight of the housing and unappealing device aesthetics.

It would therefore be desirable to be able to provide improved displaysfor electronic devices.

SUMMARY

A display in an electronic device may have an array of display pixelsthat provide image light to a user. The display may be mounted within ahousing for the electronic device.

The array of display pixels in the display may form an active displaystructure with a rectangular shape. The rectangular active displaystructure may be surrounded by an inactive display structure borderregion. Optical structures such as upper and lower optical structuresmay be configured to bend light from the display pixels that are locatedalong the periphery of the active display structure so as to enlarge theeffective size of the display.

The optical structures may include upper optical structures such as asheet of glass or other optical member having curved edge surfaces forbending light from the display pixels. The optical structures may alsoinclude lower optical structures such as strips of glass with curvedsurfaces that surround an opening or other optical structures havingcurved surfaces. The lower optical structures may bend light from thedisplay pixels located long the periphery of the active display pixels.The upper optical structures may then bend the light that has passedthrough the lower optical structures.

Further features of the invention, its nature and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an illustrative electronic device suchas a laptop computer with a display in accordance with an embodiment ofthe present invention.

FIG. 2 is a perspective view of an illustrative electronic device suchas a handheld electronic device with a display in accordance with anembodiment of the present invention.

FIG. 3 is a perspective view of an illustrative electronic device suchas a tablet computer with a display in accordance with an embodiment ofthe present invention.

FIG. 4 is a schematic diagram of an illustrative electronic device witha display in accordance with an embodiment of the present invention.

FIG. 5 is a cross-sectional side view of an illustrative display inaccordance with an embodiment of the present invention.

FIG. 6 is a top view of illustrative display layers in a display havingan active region with an array of display pixels and an inactive borderregion in accordance with an embodiment of the present invention.

FIG. 7 is a diagram showing how a mold may be used to form displaystructures such as glass structures with curved surfaces in accordancewith an embodiment of the present invention.

FIG. 8 is a diagram showing how a slumping process may be used to formdisplay structures such as glass structures with curved surfaces inaccordance with an embodiment of the present invention.

FIG. 9 is a diagram showing how a machining process may be used to formdisplay structures such as glass structures with curved surfaces inaccordance with an embodiment of the present invention.

FIG. 10 is a cross-sectional side view of an illustrative display havingoptical structures for bending light produced by an array of displaypixels and thereby creating a borderless appearance for the display inaccordance with an embodiment of the present invention.

FIG. 11 is a cross-sectional side view of an illustrative display havingupper optical structures with a concave edge portion and lower opticalstructures for bending light produced by an array of display pixels andthereby creating a borderless appearance for the display in accordancewith an embodiment of the present invention.

FIG. 12 is a cross-sectional side view of an illustrative display havingupper optical structures with curved lower surfaces and lower opticalstructures such as Fresnel lens structures for bending light produced byan array of display pixels and thereby creating a borderless appearancefor the display in accordance with an embodiment of the presentinvention.

FIG. 13 is a cross-sectional side view of an illustrative display havingupper optical structures with curved upper surfaces and lower opticalstructures with curved upper surfaces for bending light produced by anarray of display pixels and thereby creating a borderless appearance forthe display in accordance with an embodiment of the present invention.

FIG. 14 is a cross-sectional side view of an illustrative display with asolidified liquid polymer layer for supporting upper and lower opticalstructures configured to bend light produced by an array of displaypixels and thereby create a borderless appearance for the display inaccordance with an embodiment of the present invention.

FIG. 15 is a cross-sectional side view of an illustrative display havingupper and lower optical structures for bending light and having a touchsensor on an upper surface of the upper optical structures in accordancewith an embodiment of the present invention.

FIG. 16 is a cross-sectional side view of an illustrative display havingupper and lower optical structures for bending light and having a touchsensor on a lower surface of the upper optical structures in accordancewith an embodiment of the present invention.

FIG. 17 is a cross-sectional side view of an illustrative display havingupper and lower optical structures for bending light and having a touchsensor on an upper surface of the lower optical structures in accordancewith an embodiment of the present invention.

FIG. 18 is a cross-sectional side view of an illustrative display havingupper and lower optical structures for bending light and having coatinglayers on an upper surface of the upper optical structures in accordancewith an embodiment of the present invention.

FIG. 19 is a cross-sectional side view of an illustrative display havingupper and lower optical structures for bending light and having a planardisplay cover layer that covers the upper and lower optical structuresin accordance with an embodiment of the present invention.

DETAILED DESCRIPTION

Electronic devices may include displays. The displays may be used todisplay images to a user. Illustrative electronic devices that may beprovided with displays are shown in FIGS. 1, 2, and 3 .

FIG. 1 shows how electronic device 10 may have the shape of a laptopcomputer having upper housing 12A and lower housing 12B with componentssuch as keyboard 16 and touchpad 18. Device 10 may have hinge structures20 that allow upper housing 12A to rotate in directions 22 aboutrotational axis 24 relative to lower housing 12B. Display 14 may bemounted in upper housing 12A. Upper housing 12A, which may sometimesreferred to as a display housing or lid, may be placed in a closedposition by rotating upper housing 12A towards lower housing 12B aboutrotational axis 24.

FIG. 2 shows how electronic device 10 may be a handheld device such as acellular telephone, music player, gaming device, navigation unit, orother compact device. In this type of configuration for device 10,housing 12 may have opposing front and rear surfaces. Display 14 may bemounted on a front face of housing 12. Display 14 may, if desired, havea display cover layer or other exterior layer that includes openings forcomponents such as button 26. Openings may also be formed in a displaycover layer or other display layer to accommodate a speaker port (see,e.g., speaker port 28 of FIG. 2 ).

FIG. 3 shows how electronic device 10 may be a tablet computer. Inelectronic device 10 of FIG. 3 , housing 12 may have opposing planarfront and rear surfaces. Display 14 may be mounted on the front surfaceof housing 12. As shown in FIG. 3 , display 14 may have a cover layer orother external layer with an opening to accommodate button 26 (as anexample).

The illustrative configurations for device 10 that are shown in FIGS. 1,2, and 3 are merely illustrative. In general, electronic device 10 maybe a laptop computer, a computer monitor containing an embeddedcomputer, a tablet computer, a cellular telephone, a media player, orother handheld or portable electronic device, a smaller device such as awrist-watch device, a pendant device, a headphone or earpiece device, orother wearable or miniature device, a television, a computer displaythat does not contain an embedded computer, a gaming device, anavigation device, an embedded system such as a system in whichelectronic equipment with a display is mounted in a kiosk or automobile,equipment that implements the functionality of two or more of thesedevices, or other electronic equipment.

Housing 12 of device 10, which is sometimes referred to as a case, maybe formed of materials such as plastic, glass, ceramics, carbon-fibercomposites and other fiber-based composites, metal (e.g., machinedaluminum, stainless steel, or other metals), other materials, or acombination of these materials. Device 10 may be formed using a unibodyconstruction in which most or all of housing 12 is formed from a singlestructural element (e.g., a piece of machined metal or a piece of moldedplastic) or may be formed from multiple housing structures (e.g., outerhousing structures that have been mounted to internal frame elements orother internal housing structures).

Display 14 may be a touch sensitive display that includes a touch sensoror may be insensitive to touch. Touch sensors for display 14 may beformed from an array of capacitive touch sensor electrodes, a resistivetouch array, touch sensor structures based on acoustic touch, opticaltouch, or force-based touch technologies, or other suitable touch sensorcomponents.

Displays for device 10 may, in general, include image pixels formed fromlight-emitting diodes (LEDs), organic LEDs (OLEDs), plasma cells,electrowetting pixels, electrophoretic pixels, liquid crystal display(LCD) components, or other suitable image pixel structures. In somesituations, it may be desirable to use LCD components to form display14, so configurations for display 14 in which display 14 is a liquidcrystal display are sometimes described herein as an example. It mayalso be desirable to provide displays such as display 14 with backlightstructures, so configurations for display 14 that include a backlightunit may sometimes be described herein as an example. Other types ofdisplay technology may be used in device 10 if desired. The use ofliquid crystal display structures and backlight structures in device 10is merely illustrative.

A display cover layer may cover the surface of display 14 or a displaylayer such as a color filter layer or other portion of a display may beused as the outermost (or nearly outermost) layer in display 14. Adisplay cover layer or other outer display layer may be formed from atransparent glass sheet, a clear plastic layer, or other transparentstructures.

Touch sensor components such as an array of capacitive touch sensorelectrodes formed from transparent materials such as indium tin oxidemay be formed on the underside of a display cover layer, may be formedon a separate display layer such as a glass or polymer touch sensorsubstrate, or may be integrated into other display layers (e.g.,substrate layers such as a thin-film transistor layer).

A schematic diagram of an illustrative configuration that may be usedfor electronic device 10 is shown in FIG. 4 . As shown in FIG. 4 ,electronic device 10 may include control circuitry 29. Control circuitry29 may include storage and processing circuitry for controlling theoperation of device 10. Control circuitry 29 may, for example, includestorage such as hard disk drive storage, nonvolatile memory (e.g., flashmemory or other electrically-programmable-read-only memory configured toform a solid state drive), volatile memory (e.g., static or dynamicrandom-access-memory), etc. Control circuitry 29 may include processingcircuitry based on one or more microprocessors, microcontrollers,digital signal processors, baseband processors, power management units,audio codec chips, application specific integrated circuits, etc.

Control circuitry 29 may be used to run software on device 10, such asoperating system software and application software. Using this software,control circuitry 29 may present information to a user of electronicdevice 10 on display 14. Display 14 may contain an array of displaypixels (e.g., liquid crystal display pixels) that are organized in rowsand columns. Control circuitry 29 may be used to display content for auser of device 10 on the array of display pixels in display 14.

Input-output circuitry 30 may be used to allow data to be supplied todevice 10 and to allow data to be provided from device 10 to externaldevices. Input-output circuitry 30 may include communications circuitry32. Communications circuitry 32 may include wired communicationscircuitry for supporting communications using data ports in device 10.Communications circuitry 32 may also include wireless communicationscircuits (e.g., circuitry for transmitting and receiving wirelessradio-frequency signals using antennas).

Input-output circuitry 30 may also include input-output devices 34. Auser can control the operation of device 10 by supplying commandsthrough input-output devices 34 and may receive status information andother output from device 10 using the output resources of input-outputdevices 34.

Input-output devices 34 may include sensors and status indicators 36such as an ambient light sensor, a proximity sensor, a temperaturesensor, a pressure sensor, a magnetic sensor, an accelerometer, andlight-emitting diodes and other components for gathering informationabout the environment in which device 10 is operating and providinginformation to a user of device 10 about the status of device 10.

Audio components 38 may include speakers and tone generators forpresenting sound to a user of device 10 and microphones for gatheringuser audio input.

Display 14 (e.g., the array of display pixels in display 14) may be usedto present images for a user such as text, video, and still images.Sensors 36 may include a touch sensor array that is formed as one of thelayers in display 14.

User input may be gathered using buttons and other input-outputcomponents 40 such as touch pad sensors, buttons, joysticks, clickwheels, scrolling wheels, touch sensors such as sensors 36 in display14, key pads, keyboards, vibrators, cameras, and other input-outputcomponents.

A cross-sectional side view of an illustrative configuration that may beused for display 14 of device 10 (e.g., for display 14 of the devices ofFIG. 1 , FIG. 2 , or FIG. 3 or other suitable electronic devices) isshown in FIG. 5 . As shown in FIG. 5 , display 14 may include backlightstructures such as backlight unit 42 for producing backlight 44. Duringoperation, backlight 44 travels outwards (vertically upwards indimension Z in the orientation of FIG. 5 ) and passes through displaypixel structures in display layers 46. This illuminates any images thatare being produced by the display pixels for viewing by a user. Forexample, backlight 44 may illuminate images on display layers 46 thatare being viewed by viewer 48 in direction 50.

Display 14 may, if desired, have one or more optical structures that arelocated above display layers 46. For example, display 14 may have adisplay cover layer such as display cover layer 84. Display cover layer84 may be formed from a layer of clear glass, a transparent sheet ofplastic, or other transparent structure. Display cover layer 84 may bemounted in housing 12 (e.g., using housing sidewalls). During operation,light 44 may pass through the array of display pixels formed fromdisplay layers 46 and display cover layer 84 for viewing by user 48.

Display layers 46 may be mounted in chassis structures such as a plasticchassis structure and/or a metal chassis structure to form a displaymodule for mounting in housing 12 or display layers 46 may be mounteddirectly in housing 12 (e.g., by stacking display layers 46 into arecessed portion in housing 12). Display layers 46 may form a liquidcrystal display or may be used in forming displays of other types.Display layers 46 may sometimes be referred to as a display module, adisplay, or an array of display pixels. The image light (light 44) thatpasses through the array of display pixels is used in displaying contenton display 14 for user 48.

In a configuration in which display layers 46 are used in forming aliquid crystal display, display layers 46 may include a liquid crystallayer such a liquid crystal layer 52. Liquid crystal layer 52 may besandwiched between display layers such as display layers 58 and 56.Layers 56 and 58 may be interposed between lower polarizer layer 60 andupper polarizer layer 54.

Layers 58 and 56 may be formed from transparent substrate layers such asclear layers of glass or plastic. Layers 56 and 58 may be layers such asa thin-film transistor layer and/or a color filter layer. Conductivetraces, color filter elements, transistors, and other circuits andstructures may be formed on the substrates of layers 58 and 56 (e.g., toform a thin-film transistor layer and/or a color filter layer). Touchsensor electrodes may also be incorporated into layers such as layers 58and 56 and/or touch sensor electrodes may be formed on other substrates.

With one illustrative configuration, layer 58 may be a thin-filmtransistor layer that includes an array of thin-film transistors andassociated electrodes (display pixel electrodes) for applying electricfields to liquid crystal layer 52 and thereby displaying images ondisplay 14. Layer 56 may be a color filter layer that includes an arrayof color filter elements for providing display 14 with the ability todisplay color images. If desired, layer 58 may be a color filter layerand layer 56 may be a thin-film transistor layer.

During operation of display 14 in device 10, control circuitry 29 (e.g.,one or more integrated circuits such as components 68 on printed circuit66 of FIG. 5 ) may be used to generate information to be displayed ondisplay 14 (e.g., display data). The information to be displayed may beconveyed from circuitry 68 to display control circuitry such as displaydriver integrated circuit 62 using a signal path such as a signal pathformed from conductive metal traces in flexible printed circuit 64 (asan example).

Display driver integrated circuit 62 may be mounted onthin-film-transistor layer driver ledge 82 or elsewhere in device 10.During operation of display 14, display driver circuitry 62 and/or otherdisplay control circuitry such as gate driver circuitry formed onsubstrate 58 or coupled to substrate 58 may be used in controlling thearray of display pixels in layers 46 (e.g., using a grid of verticaldata lines and horizontal gate lines).

A flexible printed circuit cable such as flexible printed circuit 64 maybe used in routing signals between printed circuit 66 andthin-film-transistor layer 58. If desired, display driver integratedcircuit 62 may be mounted on printed circuit 66 or flexible printedcircuit 64. Printed circuit 66 may be formed from a rigid printedcircuit board (e.g., a layer of fiberglass-filled epoxy) or a flexibleprinted circuit (e.g., a flexible sheet of polyimide or other flexiblepolymer layer).

Backlight structures 42 may include a light guide plate such as lightguide plate 78. Light guide plate 78 may be formed from a transparentmaterial such as clear glass or plastic. During operation of backlightstructures 42, a light source such as light source 72 may generate light74. Light source 72 may be, for example, an array of light-emittingdiodes.

Light 74 from light source 72 may be coupled into edge surface 76 oflight guide plate 78 and may be distributed in dimensions X and Ythroughout light guide plate 78 due to the principal of total internalreflection. Light guide plate 78 may include light-scattering featuressuch as pits or bumps. The light-scattering features may be located onan upper surface and/or on an opposing lower surface of light guideplate 78.

Light 74 that scatters upwards in direction Z from light guide plate 78may serve as backlight 44 for display 14. Light 74 that scattersdownwards may be reflected back in the upwards direction by reflector80. Reflector 80 may be formed from a reflective material such as alayer of white plastic or other shiny materials.

To enhance backlight performance for backlight structures 42, backlightstructures 42 may include optical films 70. Optical films 70 may includediffuser layers for helping to homogenize backlight 44 and therebyreduce hotspots, compensation films for enhancing off-axis viewing, andbrightness enhancement films (also sometimes referred to as turningfilms) for collimating backlight 44. Optical films 70 may overlap theother structures in backlight unit 42 such as light guide plate 78 andreflector 80. For example, if light guide plate 78 has a rectangularfootprint in the X-Y plane of FIG. 5 , optical films 70 and reflector 80may have a matching rectangular footprint. Display layers 46 and theother display structures of FIG. 5 typically have rectangular shapeswith four peripheral edges, but display configurations with other shapesmay be used in forming display 14 if desired.

As shown in FIG. 6 , display structures 46 of display 14 may include aplurality of display pixels 86. Display pixels 86 may be organized inrows and columns. Display control circuitry may be used in controllingthe operation of display pixels 86 using signal lines such as data lines88 and gate lines 90. In liquid crystal displays, display pixels 86 mayeach contain an electrode for applying an electric field to anassociated portion of liquid crystal layer 52 (FIG. 5 ) and a thin-film(amorphous silicon or polysilicon) transistor for controlling themagnitude of the signal applied to the electrode and therefore themagnitude of the electric field. In other types of displays, displaypixels 86 may be formed from other types of structures (e.g., organiclight-emitting diodes, etc.).

Lines 90 may be coupled to the gates of the thin-film transistors andmay sometimes be referred to as gate lines. Lines 88 may be coupled tothe sources of the thin-film transistors and may sometimes be referredto as source lines or data lines. Gate driver circuitry (e.g., thin-filmtransistor gate driver circuitry) may be coupled to gate lines 90.Display driver circuitry that produces data signals for lines 88 (e.g.,a display driver integrated circuit) may be coupled to data lines 88.

Gate driver circuitry, one or more display driver integrated circuits,traces for distributing gate and data signals and other display controlsignals, and other display control circuitry may be formed in inactiveregion 461 of display 14 and display structures 46. As an example, adisplay driver integrated circuit may be mounted along the upper segmentof inactive region 461, whereas gate driver thin-film circuitry may beformed along the left and right segments of inactive region 461. Duringoperation of display 14, display pixels 86 may display images for auser, so the portion of display structures 46 containing display pixels86 may sometimes be referred to as active display structures or theactive area of display 14. The metal traces and other display controlcircuit structures in inactive region 461 do not display any images, sothis portion of structures 46 may sometimes be referred to as inactivedisplay structures.

Inactive region 461 may form a border that surrounds some or all ofactive area 46A. For example, inactive region 461 may have a rectangularring shape of the type shown in FIG. 6 having opposing upper and lowerborder segments and left and right border segments. To provide display14 with a borderless appearance, display 14 may be provided with opticalstructures such as glass layers and other structures with curved orangled surfaces. The optical structures may be configured to bend andtherefore guide light that is emitted from the array of display pixels86 in active area 46A into a portion of display 14 that overlapsinactive area 461. By using optical structures to bend light from activearea 46A, content may be displayed in portions of display 14 thatoverlap inactive regions 461, providing display 14 with a borderless ornear borderless appearance.

The optical structures that are used to enhance the apparent size ofdisplay 14 may be formed from transparent materials such as clear glassor plastic structures. As an example, the optical structures may beformed from sheets of clear glass or plastic material or from glass,plastic, or other transparent material of other shapes. Opticalstructures with curved and angled surfaces for bending light may beformed using molding equipment, slumping equipment, machining equipment,or other tools for shaping clear material.

FIG. 7 is a diagram showing how a mold may be used to form opticalstructures with curved surfaces for bending light in display 14. Asshown in FIG. 7 , molding equipment 92 may include mold structures suchas upper mold structures 94 and lower mold structures 98. Structuressuch as mold structures 94 and 98 may be heated. Optical material 102(e.g., glass, plastic, ceramic, etc.) may be molded between the opposingsurfaces of mold structures 94 and 98 (e.g., when upper mold structure94 is moved in direction 96 and/or when lower mold structures 98 ismoved in direction 100). If desired, molding operations may also involveinjection molding techniques. By molding material 102 with moldingequipment 92, optical structures 104 that have curved or angle surfacesmay be formed.

As shown in the illustrative configuration of FIG. 8 , a slumpingprocess may be used in forming optical structures with curved surfacesfor bending light in display 14. Slumping equipment 106 may include aheated metal structure or other equipment with exposed curved surfacessuch as curved surface 110. Optical material 108 (e.g., glass, plastic,ceramic, etc.) may be placed on top of surface 110 while slumpingequipment 106 is heated. When equipment 106 reaches a sufficiently hightemperature, optical material 108 will slump under its own weight,thereby creating optical structures with curved surfaces such as opticalstructures 112. Following cooling, structures 112 may be removed fromslumping equipment 106. As shown on the right-hand side of FIG. 8 , theresulting shape for optical structures 112 may have curved surfaces suchas curved upper surface 114 and curved lower surface 116.

FIG. 9 is a diagram showing how a machining process may be used to formdisplay structures such as glass structures with curved surfaces. Asshown in FIG. 9 , optical material 130 may be processed using machiningequipment 118. Machining equipment 118 may have a machining head such ashead 124 (e.g., a drill bit, milling cutter, or other machining tool).Actuator 120 may use shaft 122 to rotate head 124 in direction 126 aboutrotational axis 128. Actuator 120 may include a motor for rotating shaft122 and computer-controlled positioners for adjusting the location ofshaft 122 and head 124 relative to optical material 130. Followingmachining of the edges or other portions of optical structures 130,optical structures 130 may have curved surfaces such as curved surfaces132, as shown on the right-hand side of FIG. 9 .

By providing optical structures in display 14 with curved edges or othercurved or angled surfaces, the optical structures may bend light that isemitted from display pixels 86 in a way that allows the light to extendlaterally outward over the otherwise inactive portions of the display.As a result, it will appear to a user of the display as if the displayis borderless or nearly borderless.

To provide satisfactory light bending within tight spaces in device 10,it may be desirable to use multiple layers of light-bending structures.For example, optical structures for bending light for display 14 mayinclude a first set of structures (e.g., an optical member or otheroptical structures formed from glass, plastic, or ceramic) that arelocated lower in display 14 (i.e., closer to display structures 46) anda second set of structures (e.g., an optical member or other opticalstructures formed from glass, plastic, or ceramic) that is locatedhigher in display 14 (i.e., farther from display structures 46 andcloser to viewer 48).

An illustrative display of the type that may use curved opticalstructures to achieve a borderless or near borderless appearance to aviewer is shown in FIG. 10 . As shown in the cross-sectional side viewof display 14 in FIG. 10, display 14 may include active area displaylayers such as active display structures 46A. Inactive displaystructures such as inactive display structures 461 of FIG. 6 thatsurround the periphery of active display structures 46A are not shown.

Active area display structures 46A may contain a rectangular array ofdisplay pixels such as display pixels 86 with a rectangular peripheraledge. Light rays 44 associated with display pixels 86 may be produced bya backlight unit (e.g., a backlight unit in a display such as a backlitliquid crystal display), may be produced by light reflected off of areflector such as reflector 80 of FIG. 5 , or may be emitted bylight-emitting diode structures or other light sources within displaypixels 86.

Optical structures 134 (e.g., optical structures of the type formedusing the equipment of FIGS. 7, 8, and 9 or other equipment) may beformed from transparent optical members. For example, a display may beprovided with transparent structures formed from glass, plastic,ceramic, or other clear material. Optical structures 134 may includemultiple layers of structures such as optical structures 134T andoptical structures 134B. Optical structures 134T may be located fartherfrom active display structures 46A and closer to viewer 48 than opticalstructures 134B, so optical structures 134T may sometimes be referred toas upper or outer optical structure and optical structures 134B maysometimes be referred to lower or inner optical structures.

Optical structures 134T and 134B of FIG. 10 may have planar surfacessuch as upper surface 136 of structures 134T. Structures 134T may beformed from a sheet of material such as glass, polymer, or ceramic. Asshown in FIG. 10 , optical structures 134 and may have curved or angledsurfaces such as curved surfaces 138T on upper optical structures 134Tand curved surfaces 138B on lower optical structures 134B.

Curved surfaces may be located on the upper and/or lower sides ofoptical structures 134T and 134B. For example, in a rectangular displayhaving top, bottom, left, and right edges, curved surfaces such assurfaces 138T and/or 138B may be formed along the right and left edgesor may run around the entire periphery of the display (e.g., along theright, left, top, and bottom edges when viewed in direction 50 by viewer48).

Curved and angled surfaces in optical structures 134B and 134T may allowoptical structures 134B and 134T to serve as light bending structures tobend light 44 from active display structures 46A so that the entirelateral expanse of display 14 appears to be filled with active imagecontent. Display 14 may, for example, appear to have no left and rightborders (when viewed in direction 50) and/or may additionally have noupper and lower borders (when viewed in direction 50). The lateraldimensions (in X and Y) for active display structures 46A are less thanthe respective lateral dimensions X and Y of upper optical structures134T, so the area of structures 134T is greater than the area of activedisplay structures 46A and the apparent image size for display 14 isenlarged. By enlarging the apparent size of the display, the display maybe made to appear borderless or nearly borderless, even if activedisplay structures 46A are surrounded by a border of inactive structuressuch as structures 46B.

Rays of light from active display structures 46A such as light ray 44Mare produced by display pixels 86 that are near to the center of display14. In this portion of display 14, light may travel vertically upwardsto viewer 48 without significant bending. Light 44 in the center ofdisplay 14 may, for example, travel through a central opening in opticalstructures 134B and may travel through planar or nearly planar portionsof optical structures 134T. Near to the peripheral edges of activedisplay structures 46A, however, light rays such as light rays 44E areemitted that are bent by the curved (angled) nature of the edges ofoptical structures 134B and 134T (e.g., surfaces 138B and 138T).

As shown by the bent trajectory of light rays 44E, light rays 44E thatare emitted by display pixels 86 along the edges of active displaystructures 46A may, upon passing through optical structures 134B andbeing bent by optical structures 134B and upon passing through opticalstructures 134T and being further bent by optical structures 134T,appear to viewer 48 as if they were emitted by display pixels located ininactive border region IA. The lateral extent (e.g., width W in FIG. 10) of display 14 over which light rays 44 are emitted and therefore theeffective size of display 14 for displaying content to viewer 48 isenhanced by the presence of curved portions 138B and 138T of opticalstructures 134B and 134T, so that it appears as if display 14 has anactive area of lateral dimension W, rather than the more limited size ofactive area AA that is associated with the physical size of the array ofdisplay pixels 86 in structures 46A.

The use of multiple layers of optical structures in display 14 such aslower structures 134B and upper structures 134T (and if desired one ormore additional layers of light bending optical structures 134) allowsstructures 134 to efficiently and accurately guide light 44. Lowerstructures 134B perform some light bending and, following passagethrough a gap such as air gap G or a gap filled with a clear materialsuch as a polymer that allows rays 44E to spread out from each other,upper structures 134T may perform additional light bending. Using thelight bending capabilities of structures 134B and 134T in this way,surface 136 can be entirely covered with active display pixel content(e.g., graphics, text, video, etc.), providing display 14 with aborderless or nearly borderless appearance, despite the presence ofdisplay control circuitry and other inactive structures in inactiveregion 461 of display structures 46 (FIG. 6 ).

As shown in the illustrative example of FIG. 10 , optical structures134B may have a central opening overlapping the center of active displaystructures 46A. Light rays such as rays 44M may pass through thisopening. Optical structures 134B may also have curved surfaces 138B thatare located on the upper surface of structures 134B near the peripheraledge of display structures 46A. Structures 134B may have a rectangularoutline (shape) when viewed in direction 50 (i.e., structures 134B maybe formed from a rectangular ring-shaped member of optical material orother optical structures with curved edge surfaces). One or more, two ormore, three or more, or four of the edges of rectangular opticalstructures 134B may be provided with curved surfaces such as surfaces138B. Upper optical structures 134T may be formed from a glass membersuch as a sheet of glass with one or more curved or angled surfaces, aceramic or plastic member with one or more curved or angled surfaces, orother optical structures configured to bend light 44E.

FIG. 11 shows how the lower surface of optical member 134T may, ifdesired, be provided with a concave curved surface shape. Upper surface136 of optical member 134T may be planar. The lower surface of opticalstructures 134B in this type of configuration may be planar and may lieagainst the planar upper surface of structures 46A (as an example).Upper surfaces 138B of lower optical structures 134B may be angled orcurved (as examples). An opening (e.g., a rectangular opening) may beformed in the center of optical structures 134B.

If desired, optical structures such as optical structures 134B and 134Tmay include Fresnel lenses. As shown in FIG. 12 , for example, loweroptical structures 134B may be Fresnel lens structures having Fresnellens sections that form respective curved or angled surfaces such assurfaces 138B-1, 138B-2, 138B-3, and 138B-4. Fresnel lens structures maybe used to bend light in display 14, as described in connection withoptical structures 134B of FIG. 10 . The thickness T of Fresnel lensstructures such as optical structures 134B of FIG. 12 may be thinnerthan comparable light-bending structures that are not based on Fresnellens structures, allowing the thickness of display 14 to be minimized.

In the configuration of FIG. 13 , display 14 has been provide with upperoptical structures 134T that have an upper surface with a planar centralregion and curved peripheral edge portions 138T. The lower surface ofoptical structures 134T may be planar. Lower optical structures 134B mayhave curved upper surfaces 138B.

Optical structures 134B may be mounted against active display structures46A or may be mounted so that an air gap or a gap filled with materialsother than air such as solidified liquid polymer is formed betweenoptical structures 134B and active display structures 46A. An air gap ora gap filled with materials other than air such as solidified liquidpolymer may also be formed between the lower surface of upper opticalstructures 134T and the upper surface of lower optical structures 134B.

FIG. 14 is a cross-sectional side view of display 14 in a configurationin which optical structures 134B have been mounted so that there is noair gap between the lower surfaces of optical structures 134B and theupper surface of active display structures 46A and so that clearmaterial such as solidified liquid polymer 144 has been formed in thegap between upper optical structures 134T and the upper surfaces ofoptical structures 134B and active display structures 46A. Polymer layer144 may be used to help attach upper optical structures 134T to device10.

Polymer material 144 may be formed from a cured optical adhesive (e.g.,optically clear adhesive). Optical structures 134B may be attached todisplay structures 46A using adhesive (as an example). Polymer 144(e.g., uncured liquid polymer) may be placed on top of displaystructures 46A and 134B by dripping, screen printing, spraying, or othersuitable techniques. Optical structures 134T may then be placed on topof the liquid polymer. Ultraviolet light curing or thermal curingtechniques may then be used to cure the polymer material to form solidpolymer support structures such as structures 144 of FIG. 14 . Polymerlayer 144 may have an index of refraction of 1.1 to 1.3 or less than 1.3(as examples). Optical structures 134 may have an index of refraction of1.4 to 1.8 or 1.3 to 1.7 (as examples).

If desired, device 10 may be provided with touch sensor functionality. Atouch sensor for device 10 may be implemented using an array ofcapacitive touch sensor electrodes (e.g., transparent conductiveelectrodes such as indium tin oxide electrodes), may use resistive touchtechnology, light-based touch sensors, acoustic touch sensor technology,or other touch sensor technology. As an example, a capacitive touchsensor for device 10 may be implemented using a one-sided or two-sidedarray of indium tin oxide electrodes. The electrodes may be formed on atouch sensor substrate such as a layer of glass or plastic that isseparate from other layers in display 14 (e.g., a touch sensor substratethat is mounted within display 14 using adhesive) or may be formed onthe surface of optical structures 134T, a display cover layer that islocated above structures 134T, optical structures 134B, displaystructures 46, or other structures in display 14.

FIG. 15 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the upper surface ofoptical structures 134T. An air gap or polymer-filled gap may separateoptical structures 134T from display structures 46A and opticalstructures 134B. Touch sensor 146 may include capacitive touch sensorstructures such as a one-layer or two-layer array of indium tin oxideelectrodes. The indium tin oxide electrodes or other touch sensorstructures for touch sensor 146 may be formed directly on the uppersurface of optical structures 134T or may be formed on a substrate(e.g., a sheet of glass or polymer) that is attached to the surface ofoptical structures 134T by adhesive (as examples).

In the illustrative configuration of FIG. 16 , touch sensor 146 has beenformed on the lower surface of optical structures 134T (directly or byattaching a touch panel substrate with electrodes to the lower surfaceof structures 134T using adhesive). An air gap or a gap filled withpolymer 144 may be interposed between touch sensor 146 and displaystructures 46A and optical structures 134B.

FIG. 17 is a cross-sectional side view of display 14 in a configurationin which touch sensor 146 has been formed on the upper surface ofdisplay structures 46A and upper surfaces 138B of lower opticalstructures 134B. Touch sensor 146 may, for example, be formed on aflexible substrate such as a sheet of polymer that is attached to theupper surface of display structures 46A and the upper surfaces ofoptical structures 134B by adhesive. Touch sensor structures may also beformed on structures 46A and 134B using physical vapor deposition orother deposition techniques (e.g., to form patterned indium tin oxideelectrodes, etc.). An air gap or a gap filled with polymer 144 may beinterposed between touch sensor 146 and structures 134T.

As shown in FIG. 18 , optical structures 134 in display 14 such as upperoptical structures 134T and lower optical structures 134B may beprovided with optical coating layers such as layers 142. In the exampleof FIG. 18 , the upper surface of upper optical structures 134T havebeen coated with coating layers 142. This is merely illustrative. Theupper and/or lower surfaces of upper optical structures 134T may beprovided with coating layers 142, the upper and/or lower surfaces oflower optical structures 134T may be provided with coating layers 142,and/or both optical structures 134T and 134B may have one or moresurfaces covered with coating layers 142.

Layers 142 may be formed from dielectrics such as sputtered oxides, fromclear materials deposited using physical vapor deposition, chemicalvapor deposition, or other deposition techniques (e.g., coatings ofglass, polymer, ceramic, or other materials), or may be formed fromother transparent coating layers on optical structures 134. There may beone or more layers 142, two or more layers 142, three or more layers142, or four or more layers 142. Layers 142 may include layers such asantireflection layers (e.g., dielectric stacks with alternatinghigh-index-of-refraction and low-index-of-refraction layers), antismudgelayers, antiscratch layers, or other layers to modify the properties ofthe upper and/or lower surface of optical structures 134. An air gap ora gap filled with polymer 144 may separate the lower surface (coated oruncoated with layers 142) of upper optical structures 134T from theupper surface (coated or uncoated with layers 142) of lower opticalstructures 134B and touch sensor 146 of FIG. 18 .

In the illustrative configuration of FIG. 19 , optical structures 134such as upper optical structures 134T have been covered with a layer oftransparent material such as display cover layer 140. Display coverlayer 140 may be a planar sheet of glass, plastic, ceramic, or othertransparent material having opposing planar upper and lower surfaces.Optical structures 134T may have a planar upper surface such as uppersurface 136. Upper surface 136 may be coplanar with the planar lowersurface of display cover layer 140. Display cover layer 140 may, ifdesired, by coupled to optical structures 134T using a layer ofadhesive. Coating layers 142 may, if desired, be formed on the upperand/or lower surface of display cover layer 140. A touch sensor such astouch sensor 146 may be interposed between the lower surface of displaycover layer 140 and the upper surface of upper optical structures 134T.

Lower structures 134B may have curved or angled edge surfaces 138B thatlie in planes that are not coplanar with upper surface 136 to allow theedges of optical structures 134B to bend light from display structures46A. Light may also be bent by the curved or angled surfaces of displaystructures 134T such as surfaces 138T. Air gaps or gaps filled withpolymer 144 may separate display cover layer 140, optical structures134T, optical structures 134B, and/or display structures 46A of FIG. 20.

The foregoing is merely illustrative of the principles of this inventionand various modifications can be made by those skilled in the artwithout departing from the scope and spirit of the invention.

What is claimed is:
 1. An electronic device comprising: active displaystructures that include an array of pixels with a peripheral edge, thearray of pixels having a first area; an optical structure that overlapsand extends across an entirety of the array of pixels, wherein theoptical structure redirects light from the active display structures toa second area that is larger than the first area, the optical structurehas a first surface that faces the array of pixels and an opposingsecond surface, and the second surface has a planar portion and curvededge portions; and a touch sensor on the first surface.
 2. Theelectronic device defined in claim 1 wherein the optical structure is afirst optical structure, the electronic device further comprising: asecond optical structure interposed between the first optical structureand the array of pixels, wherein the second optical structure isconfigured to redirect the light from the active display structures. 3.The electronic device defined in claim 2 wherein the second opticalstructure comprises at least one lens.
 4. The electronic device definedin claim 3 wherein the at least one lens is a Fresnel lens.
 5. Theelectronic device defined in claim 4 wherein the Fresnel lens has acentral opening over the active display structures through which lightpasses from a portion of the array of pixels without being redirected bythe Fresnel lens.
 6. The electronic device defined in claim 5 whereinthe Fresnel lens and the first optical structure are formed fromtransparent materials.
 7. The electronic device defined in claim 6wherein the Fresnel lens comprises a material selected from the groupconsisting of: glass, plastic, and ceramic.
 8. The electronic devicedefined in claim 2 wherein the second optical structure has edgeportions that are overlapped by the curved edge portions of the firstoptical structure.
 9. The electronic device defined in claim 8 whereinthe edge portions of the second optical structure are separated by a gapand wherein the planar portion of the first optical structure overlapsthe gap.
 10. The electronic device defined in claim 1 furthercomprising: a glass display cover layer that overlaps the opticalstructure.
 11. The electronic device defined in claim 10 furthercomprising: a speaker port; and wireless communications circuitryconfigured to transmit and receive radio-frequency signals.
 12. Anelectronic device, comprising: an array of pixels having a first area; afirst optical structure that overlaps the array of pixels, wherein thefirst optical structure has a surface with a curved portion and a planarportion; and a second optical structure interposed between the firstoptical structure and the array of pixels, wherein the second opticalstructure is overlapped by the curved portion and the planar portion ofthe first optical structure, the first and second optical structuresredirect light from the array of pixels to a second area that is largerthan the first area, the second optical structure is separated from thefirst optical structure by a gap, and the planar portion of the firstoptical structure overlaps the gap.
 13. The electronic device defined inclaim 12 wherein the surface with the curved portion and the planarportion is a first surface facing the array of pixels, and the firstoptical structure has an opposing second surface.
 14. The electronicdevice defined in claim 13 wherein the second surface is planar.
 15. Theelectronic device defined in claim 13 wherein the curved portion isconvex.
 16. The electronic device defined in claim 12 wherein the firstoptical structure has a first surface facing the array of pixels, andwherein the surface with the curved portion and the planar portion is anopposing second surface.
 17. The electronic device defined in claim 16wherein the first surface is planar, the electronic device furthercomprising: a touch sensor on the first surface.
 18. The electronicdevice defined in claim 12 further comprising: optically clear adhesivehaving opposing first and second surfaces, wherein the first surfacedirectly contacts the first optical structure and wherein the secondsurface directly contacts the second optical structure.
 19. Theelectronic device defined in claim 12 further comprising: a touch sensorformed on the surface of the first optical structure.
 20. An electronicdevice comprising: a housing having a rear surface and sidewalls thatextend from the rear surface; and a display mounted in the housing, thedisplay comprising: an array of pixels; a first optical structure thatoverlaps the array of pixels, wherein the first optical structure has afirst surface that faces the array of pixels and an opposing secondsurface, and the second surface has curved edge portions and a planarcentral portion; and a second optical structure interposed between thearray of pixels and the first optical structure, wherein the secondoptical structure has curved portions that are at least partiallyoverlapped by the curved edge portions of the first optical structure.